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Comment by wnevets | Hacker News Reader

const doesn't actually stop data from changing, just reassignment.

  const user = {id: 1, status: 'active'};
  user.status = 'disabled';

is valid javascript

You're talking about two different things. In this case, you'd use...

    const user = Object.freeze({id: 1, status: 'active'});

But const is immaterial to this topic, as it only prevents you from being able to reassign user to some other value, i.e.,

    user = 7;

While...

    let user = Object.freeze({id: 1, status: 'active'});
    user.status = 'disabled'; // throws an error.

Provides the behavior that you're seeking to guard against, regardless of let/var/const usage.

>You're talking about two different things. In this case, you'd use...

No, I'm talking about the behavior of const.

That is how object oriented languages work. It is a constant reference to a mutable object.

  final int[] arr = {1, 2, 3};
  arr[1] = 10;

is valid Java.

Which is to say that the const pointer itself doesn't change. It doesn't impose any constraints on the values of any underlying data structures.

Javascript could use some proper immutable types.

I've wondered why the JS people didn't call their keyword for this purpose "final" like Java did.